The present invention relates to a sintered body useful for cutting operations such as preferably milling and turning.
In Swedish patent applications 8405667-0 (U.S. patent application Ser. No. 06/791,556) and 8503804-0 it has been shown that an increased strength was obtained in sintered bodies of cemented carbide used in tools for rock drilling and also in wear parts by manufacturing said sintered body so that its core comprises a fine grained eta phase, M.sub.6 C (e.g. Co.sub.3 W.sub.3 C) and/or M.sub.12 C (e.g. Co.sub.6 W.sub.6 C), embedded in normal alpha (WC) + beta (Co binder phase) structure at the same time as the sintered body has a surrounding surface zone which consists merely of alpha + beta-phase. Furthermore, said surface zone has an outer part with low content of beta-phase, (binder phase), and an inner part - between the outer paart and the eta phase containing core - which has a high content of binder phase.